Battery Module Including Busbar Hole

This application claims benefit of priority to Korean Patent Application No. 10-2024-0043685 filed on Mar. 29, 2024 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

The present disclosure generally relates to a battery module including a busbar hole.

Unlike a primary battery, a secondary battery may be easily charged and discharged, such that a secondary battery has been widely used as a power source for various mobile devices and electric vehicles.

The secondary battery may include battery cells in which an electrode assembly formed by stacking a positive electrode plate, a negative electrode plate, and a separator or by winding the components in a roll shape is accommodated in a case. A plurality of battery cells may be stacked in a predetermined direction and may be accommodated in a battery module or a battery pack.

A battery cell may generate heat due to an electrochemical reaction while being charged and discharged. In case heat is not discharged, heat may continuously accumulate in an internal space of the battery module or the battery pack, which may result in reduced performance or a risk of fire.

Thus, research on a structure in which a battery cell may be cooled more effectively may be necessary.

An example embodiment of the present disclosure is to prevent a busbar from being overcooled by cooling fluid.

An example embodiment of the present disclosure is to allow cooling fluid to smoothly pass through a busbar.

The present disclosure may be widely applied in green technology fields such as an electric vehicle, a battery charging station, and a solar power generation and wind power generation using batteries. Also, the present disclosure may be used in an eco-friendly electric vehicle, a hybrid vehicle, or the like, to prevent climate change by suppressing air pollution and greenhouse gas emissions.

According to an aspect of the present disclosure, a battery module includes a housing including an accommodation space in which a cooling fluid is accommodated; a cell assembly including a plurality of battery cells stacked in a first direction in the accommodation space and each including a lead tab; and a busbar assembly disposed to face the cell assembly in the accommodation space, and including a plurality of busbars electrically connected to the plurality of battery cells, and a support plate supporting the busbar, wherein the busbar includes a plurality of slit holes into which the lead tab is inserted; and at least one busbar hole disposed between the plurality of slit holes and allowing cooling fluid to flow therethrough.

The cell assembly includes at least one of a cell pad disposed between the plurality of battery cells and preventing heat transfer between the plurality of adjacent battery cells or a cooling fin provided to exchange heat with the plurality of adjacent battery cells, and the busbar hole is disposed to face at least one of the cell pad or the cooling fin.

The battery module may further include an end plate disposed to face the cell assembly with the busbar assembly therebetween, and including at least one plate hole through which cooling fluid passes, wherein a center of the busbar hole is spaced apart from a center of the plate hole by a predetermined distance in the first direction so as to not overlap the plate hole.

The support plate may include at least one pass hole disposed between the plurality of busbars and allowing cooling fluid to pass therethrough.

The battery module may further include an end plate disposed to face the cell assembly with the busbar assembly therebetween, and including at least one plate hole through which cooling fluid passes, wherein the pass hole is disposed such that at least a portion of the pass hole overlaps the plate hole in the second direction perpendicular to the first direction.

The busbar hole and the pass hole may be disposed alternately in the first direction.

The busbar assembly may further include an insulating panel disposed between the support plate and the cell assembly, and the insulating panel includes at least one panel hole communicating with the busbar hole in the second direction facing the cell assembly.

The support plate may include at least one support hole communicating with the busbar hole, and the support hole may be disposed parallel to the busbar hole such that at least a portion of the support hole overlaps the busbar hole in the second direction.

The busbar hole may be disposed parallel to the panel hole such that at least a portion of the busbar hole overlaps in the second direction.

The busbar hole may be spaced apart from a center of the panel hole by a predetermined distance in a third direction perpendicular to both the first direction and the second direction such that the busbar hole does not overlap the panel hole in the second direction.

The busbar assembly may include a busbar guide guiding a flow of cooling fluid passing through the busbar hole.

The busbar assembly may further include an insulating panel disposed between the support plate and the cell assembly, and the busbar guide extends from the busbar into a space between the busbar and the insulating panel.

The embodiments of the present disclosure are illustrated in embodiments with reference to the accompanying drawings.

Before starting the detailed description of example embodiments, it should be noted that terms or words used in the descriptions and claims should not be interpreted in a limiting sense.

The same reference numbers or symbols in each drawing represent portions or components performing substantially the same function. For ease of description, the same reference numbers or symbols may be used in different example embodiments.

An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. The terms, “include,” “comprise,” “is configured to,” or the like of the description are used to indicate the presence of features, numbers, steps, operations, elements, portions or combination thereof, and do not exclude the possibilities of combination or addition of one or more features, numbers, steps, operations, elements, portions or combination thereof.

In the description below, the terms “upper side,” “upper portion,” “lower side,” “lower portion,” “side surface,” front surface,” and “rear surface,” and the like, are denoted based on the direction in the drawing, and it is noted that the terms may be denoted differently when the direction of the object changes.

The terms “first,” “second,” and the like may be used to distinguish one element from the other, and may not limit a sequence and/or an importance, or others, in relation to the elements. In some cases, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of right in the example embodiments.

is a perspective diagram illustrating a battery module according to an example embodiment.is an exploded perspective diagram illustrating a battery module according to an example embodiment.is an enlarged diagram illustrating a portion of a cross-section taken along line I-I′ in.is a diagram illustrating a flowing direction of cooling fluid in.

According to an example embodiment, a battery modulemay include a housingincluding an accommodation space S in which cooling fluid is accommodated, a cell assemblydisposed in the accommodation space S and including a plurality of battery cellsincluding a lead tab, a busbar assemblydisposed to face the cell assemblyin the accommodation space S and including a busbarelectrically connected to the plurality of battery cellsand a support platesupporting the busbar. Here, according to an example embodiment, the busbarmay include a plurality of slitinto which the lead tabis inserted, and at least one busbar holedisposed between the plurality of slitsand including cooling fluid to enable flow therein.

The structure of the busbar holedescribed above will be described in greater detail later inand below, and the structure in which cooling fluid flows in the housingwill be described first with reference to.

According to an example embodiment, the accommodation space S may include a cell assemblyaccommodated in the accommodation space S and including a plurality of battery cellsand a cooling portmounted on the housingand supplying cooling fluid to the accommodation space S or discharging the supplied cooling fluid externally of the housing. Also, the cooling portmay include an inlet port(“first cooling port”) supplying cooling fluid to the accommodation space S and an outlet port(“second cooling port”) discharging cooling fluid supplied to the accommodation space S externally of the housing. Here, the inlet portand the outlet portmay be disposed at different levels.

Specifically, the outlet portmay be disposed above the inlet portin the direction in which the cooling fluid rises in the accommodation space S (the height direction, or the +Z-axis direction). Accordingly, the relatively substantial amount of the cooling fluid may be accommodated in the accommodation space S.

Here, the notion that “the outlet portis disposed above the inlet port” may be represented from the perspective of the flow of the cooling fluid, and may indicate that the portion(an emit end) into which the cooling fluid of the outlet portflows is disposed above the portion(discharge end) into which the cooling fluid is discharged from the inlet port. Here, “disposed above” may indicate the +Z-axis direction in the drawing or the direction in which the cooling fluid rises in the accommodation space S.

As for the cooling port, with respect to the flow of cooling fluid, the component disposed on the upstream side on which the fluid flows in may be referred to as an inlet port(first port), and the component disposed on the downstream side may be referred to as an outlet port(second port). The inlet portand the outlet portmay be denoted as above for distinguishing the arrangement positions, and the specific configurations thereof may be the same.

The cooling fluid in the example embodiments may refer to fluid acting as an electrical insulator, such as an insulating oil of which a main component is non-conductive oil. However, the cooling fluid in the example embodiment is not limited thereto, and any fluid having the property of cooling the battery cellthrough heat exchange with the battery cellmay be included.

The housingmay include a first coverdisposed on the upper side of the cell assemblyand a second coversupporting a lower portion of the cell assembly. The first coverand the second covermay be coupled to and face each other with the cell assemblyinterposed therebetween in the height direction (Z-axis direction). The first coverand the second covermay be coupled to each other and may form an accommodation space S therein.

According to an example embodiment, the side plateand the side covermay be disposed in the direction perpendicular to the stacking direction of the cell assembly(the X-axis direction in the drawing). The side plateand the side covermay include an electrically insulating material and may protect the cell assemblyfrom external impacts.

Also, the battery modulein the example embodiment may include a busbar assemblydisposed so as to face at least one side of the cell assemblyand to electrically connect the plurality of battery cellsto each other, and a circuit portionconnected to the plurality of battery cellsand receiving a temperature or current value. The circuit portionmay be connected to a battery management system (BMS).

The cell assemblymay include the plurality of battery cellsstacked in a predetermined direction (e.g., the X-axis direction in the drawing), a plurality of cell padsdisposed between the plurality of battery cells, and a cooling findisposed between the plurality of battery cellsand the plurality of cell padsand performing cooling (see).

Each of the plurality of battery cellsmay include a caseaccommodating an electrode assembly (not illustrated) formed by stacking a positive electrode plate and a negative electrode plate, and a lead tabelectrically connected to the electrode assembly and protruding from at least one side of the case.

The electrode assembly may be configured such that the positive electrode plate and the negative electrode plate are stacked in a state in which wide surfaces thereof may face each other with a separator interposed therebetween. The separator may be configured to prevent electrical shorting between the positive electrode plate and the negative electrode plate and to generate ion flow. For example, the separator may include a porous polymer film or a porous nonwoven fabric.

Also, the electrode assembly may be a jelly roll type formed by being wound in the predetermined direction, and may be accommodated in the case in various manners, such as a stacking type, a zigzag folding type, a stack-folding type, or the like.

The plurality of battery cellsmay be a secondary battery of a pouch type, a prismatic type, or a cylindrical type, depending on the structure of the case. In the drawing, in the battery cell, the caseis a pouch cell in the shape of a pouch, but an example embodiment thereof is not limited thereto.

The busbar assemblymay include a plurality of busbarselectrically connecting the plurality of battery cellsto each other and a support plateon which the plurality of busbarsare mounted.

In example embodiments, the lead tabsof the battery cellsmay protrude on both sides in a direction perpendicular to the stack direction (e.g., the Y-axis direction in the drawing), and accordingly, the busbar assemblymay be disposed on both sides of the cell assembly. In this case, the structures of the first busbar assemblydisposed on one side of the cell assemblyand the second busbar assemblydisposed on the other side may be configured the same and merely the positions thereof may be different.

The example embodiment is not limited to the example in which the busbar assemblyis disposed on both sides, and any example in which the busbar assemblyis disposed on at least one side may be included in the example embodiment.

The cell padmay be disposed between the plurality of battery cellsand may bond or absorb vibration or impact between the plurality of adjacent battery cells. For example, the cell padmay include a material having low thermal conductivity and may prevent heat transmission between adjacent battery cells. Accordingly, when an abnormal event occurs in one battery cell, heat may be prevented from transmitting to adjacent battery cells. However, an example embodiment thereof is not limited thereto, and the cell padmay be formed of a material having high thermal conductivity.

The cooling finmay include a material having high thermal conductivity. The cooling finmay be disposed between the plurality of battery cellsand may exchange heat with the plurality of adjacent battery cellsin contact with each other. The body portionof the cooling finmay be in contact with the case of the battery celland may exchange heat with the case, and may exchange heat with the cooling fluid through the bent portionsandincluded on both sides ends of the body portion(see).

The busbarmay include two or more slitsinto which the lead tabsof the plurality of battery cellsare inserted, respectively. The busbarmay electrically connect the electrode terminal, electrically connected to an external power source, to the lead tab.

The support platemay support the plurality of busbars, and may have a plurality of pass holesthrough which the cooling fluid flows. A plurality of the pass holesmay be included between the plurality of busbarsin the vertical direction (e.g., the Z-axis direction in the drawing).